This invention relates to an improved arrangement for powering electrical components in absolute length- or angle-measuring devices of the type which include a coded scale; a scanning unit for reading the coded scale, which scanning unit contains a code generator which includes a plurality of electrical components; means for generating a brief duration switching signal; and means for generating a supply voltage between a pair of voltage supply terminals.
In the position measuring devices of the general type described above, it is standard practice in order to save current to switch on the electrical components of the code generator only briefly during the interrogation of absolute position values. It is known practice to have this switching on and off of the supply voltage controlled by a computer. Furthermore, if the electrical components in the code generator, such as light-emitting diodes, for example, are connected over long lines to a current supply apparatus, then it is standard practice to connect a capacitor in parallel to these components. This practice is especially helpful in the case of high switching frequencies. The diodes which illuminate a coded scale have a relatively high current requirement in the brief switching on of the code generator, and the current source and supply lines must be laid out correspondingly.